TURSDAY August 6, 2008 (foodconsumer.org) -- A Japanese study led by Suzuki T and colleagues Aichi Cancer Center Research Institute in Chikusa-ku, Nagoya, Japan from suggests that the preventative effect of soybean products against breast cancer depends on the receptor status.

The study published in the Oct. 1, 2008 issue of the International Journal of Cancer showed that those who were in the tertile consuming the highest amount of soy were more than 22 percent less likely to have breast cancer of different receptors.

Specifically, those who consumed the highest amount of soy were 26 percent less likely to have estrogen receptor (ER+) positive breast cancer and 22 percent less likely to have human epidermal growth factor receptor 2 positive (HER2) tumors.

But when all three types were considered together, 27 percent reduced risk was found only in patients with ER+/HER2-/progesterone receptor positive (PR+) tumor, the researchers found.

The case-control study involved 678 cases of breast cancer and 3,390 age and menopausal status-matched noncancer patients.

The researchers concluded that "These findings indicate that the protective effect of soy against breast cancer risk differs by receptor status."

Breast cancer is diagnosed in 190,000 men and women and kills about 59,000 each year in the United States.